blood pressure chart nhs calculator

How to use this blood pressure chart NHS calculator

This calculator is designed to help you quickly interpret a blood pressure reading and compare it to commonly used NHS thresholds. Blood pressure is written as two numbers:

• Systolic (top): pressure when your heart pumps blood.
• Diastolic (bottom): pressure when your heart rests between beats.

Enter both numbers, choose whether the reading was taken at home or in clinic, and press Calculate. The result will show a category and practical next steps.

Quick NHS blood pressure chart

Category	Clinic reading (approx)	Home average (approx)	What it usually means
Low blood pressure	< 90/60	< 90/60	May be normal for some people, but can cause dizziness/faintness in others.
Ideal	90/60 to 120/80	90/60 to 120/80	Healthy target range for most adults.
Normal / mildly raised	Up to 139/89	Up to 134/84	Usually not hypertension, but worth monitoring over time.
High blood pressure (hypertension)	140/90 or higher	135/85 or higher	Higher risk of stroke, heart disease, and kidney disease if persistent.
Severely high	180/120 or higher	180/120 or higher	Urgent assessment needed, especially with symptoms.

Why home and clinic readings can be different

Many people show higher readings in medical settings because of stress or anxiety (sometimes called the “white coat effect”). That is why NHS guidance uses different thresholds for clinic readings versus home averages.

If you monitor at home, record readings at the same times each day and look at trends instead of one isolated number.

How to measure your blood pressure correctly at home

Before measuring

• Avoid caffeine, smoking, and exercise for at least 30 minutes beforehand.
• Empty your bladder and rest quietly for 5 minutes.
• Sit with your back supported and feet flat on the floor.

During measuring

• Use a validated upper-arm monitor if possible.
• Keep your arm supported at heart level.
• Do not talk while the cuff inflates.
• Take two readings 1 minute apart and note both.

After measuring

• Track readings over several days.
• Share repeated high readings with your GP practice.
• Use averages, not a single spike, when reviewing risk.

Understanding your result

Ideal or normal range

Great sign. Keep your current healthy habits: balanced diet, regular movement, good sleep, and stress management.

High blood pressure range

If your readings are repeatedly high, book a review with your GP. Persistent hypertension often has no symptoms, so routine checks matter.

Severely high range

Repeat the reading after 5 minutes of rest. If it remains very high, seek urgent medical advice. If you also have warning symptoms, call emergency services immediately.

Low blood pressure range

Low blood pressure can be normal for some people. If you feel dizzy, weak, faint, or unwell, speak with a clinician to check for dehydration, medication effects, or other causes.

Ways to improve blood pressure naturally

• Reduce salt intake and eat more fruit, vegetables, and whole foods.
• Stay physically active most days of the week.
• Maintain a healthy weight and waist size.
• Limit alcohol and stop smoking.
• Manage stress with breathing, walking, mindfulness, or structured support.
• Take prescribed medication consistently if advised by your clinician.

Important safety reminder

This blood pressure chart NHS calculator is a quick guide, not a replacement for professional care. If results are repeatedly outside normal ranges, or if you feel unwell, contact your GP or NHS 111. For severe symptoms or suspected stroke/heart attack, call 999 immediately.